diff --git a/Makefile b/Makefile
index c36c13b0222..a2aa24da905 100644
--- a/Makefile
+++ b/Makefile
@@ -25,7 +25,7 @@ GO_GCFLAGS := $(shell if $(GO) version|grep -q gccgo; then echo "-gccgoflags"; e
 NPROCS := $(shell nproc)
 export GO_BUILD=$(GO) build
 export GO_TEST=$(GO) test -parallel=$(NPROCS)
-RACEFLAGS := $(shell $(GO_TEST) -race ./pkg/dummy > /dev/null 2>&1 && echo -race)
+RACEFLAGS ?= $(shell $(GO_TEST) -race ./pkg/dummy > /dev/null 2>&1 && echo -race)
 
 COMMIT_NO ?= $(shell git rev-parse HEAD 2> /dev/null || true)
 GIT_COMMIT ?= $(if $(shell git status --porcelain --untracked-files=no),${COMMIT_NO}-dirty,${COMMIT_NO})
diff --git a/contrib/cirrus/test.sh b/contrib/cirrus/test.sh
index 2ee945ec000..aad33ebe36c 100755
--- a/contrib/cirrus/test.sh
+++ b/contrib/cirrus/test.sh
@@ -67,7 +67,13 @@ else
             showrun make validate
             ;;
         unit)
-            showrun make test-unit
+	    race=
+            if [[ -z "$CIRRUS_PR" ]]; then
+               # If not running on a PR then run unit tests
+               # with appropriate `-race` flags.
+               race="-race"
+            fi
+            showrun make test-unit RACEFLAGS=$race
             ;;
         conformance)
             # Typically it's undesirable to install packages at runtime.